Westclox Big Ben Electric Alarm Clock

This is the first of the electric Big Ben alarm clocks, introduced in mid 1931 and marketed through 1934. The clock pictured, Model 820, has a black Bakelite case. Model 830 with luminous numerals and hands, and Model 840 with a mahogany case, were introduced at the same time. They are powered by Sangamo self-starting synchronous motors. The motor runs the clock as well as winds the alarm mainspring. There is a key on the back for manually winding the alarm mainspring. Designed by Martin H. Kaefer.